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Thursday, 17 October 2013

Lexus LFA Nurburgring

Lexus LFA Nurburgring

The Lexus LFA is a two-seat supercar from Lexus. It is the second model in the F marque line of performance vehicles from Lexus, following the IS F. Three concept versions have been shown, each debuting at the North American International Auto Show with the LF-A designation as part of the LF Series concept line. After beginning development in the early 2000s (codenamed P280), the first LF-A concept premiered in 2005, followed in 2007 by a second LF-A with a more completely furnished interior and exterior. The third version of the LF-A, a roadster model, premiered in 2008. The production model, trademarked LFA, was shown at the Tokyo Motor Show in October 2009.

The production Lexus LFA features a new V10 engine and a carbon fiber-reinforced polymer (CFRP) body. CFRP materials account for 65 percent of the LFA's body composition by mass. The LFA went into production in late 2010, with a base price of US$375,000. A circuit-tuned variant debuted in 2012 with a base price of US$445,000,[6] making it one of the most expensive Japanese road car ever built.[7] Production ended in December 2012 with 500 vehicles completed, the final version being a Nürburgring Package model.

Nürburgring Package

On March 15, 2010, Lexus detailed the circuit-tuned variant of the LFA, plans for which were first disclosed at the LFA official press launch the previous October.[63] The variant is officially known as the LFA Nürburgring Package in reference to the similar setup
employed on the LFA race vehicles at the 24 Hours Nürburgring.

The package features an extra 10 bhp (7 kW) from its V10 engine, bringing the total to 563 bhp (420 kW; 571 PS). It also features a re-calibrated transmission with gear shifts made faster by 0.05 seconds, a front splitter, stiffer and more adjustable suspension, lightweight alloy wheels coated in track rubber, aerodynamic canards at the sides of the front bumper, and a large fixed rear wing.The LFA with the Nürburgring Package is a competition-focused variant, and will be available in four exterior colors, namely glossy black, matte black, orange, and whitest white.[65] The production totals are to be included in the 500-unit total LFA planned build cycle, and will be limited to a 50-unit run. At a base price of US$445,000, buyers will receive training sessions at the Nordschleife, accompanied by Nürburgring chief instructors, a one-night stay at the Lindner Congress and Motorsport Hotel Nürburgring, admission to the ring°werk leisure park, a Nürburgring branded jacket, and a one-year pass to the circuit.

The Nürburgring Package LFA was tested at the Nürburgring in June 2011. Driven by Akira Iida, the LFA set a time of 7:14.64 (video confirmed), the 10th-fastest time ever for a production vehicle. Lexus confirmed that this lap video was recorded as a "warm up" video for the "ADAC 24-hours" for exhibition purposes. The LFA hit 292 km/h (181 mph) on the last straight uphill climb, which is one of the highest speeds achieved by a stock exotic supercar on that segment of the track. Standard OEM Bridgestone Potenza RE70 performance street tires were used.

On September 2, 2011 reports came from Lexus via Twitter as well as Chris Harris of Evo Magazine that the Lexus LFA Nürburgring Package completed a lap of the Nurburgring in 7:14.64 with a top speed of 298 km/h on the "Dottinger" uphill climb, the fifth fastest time ever for a production car, and almost ten seconds quicker than the Porsche 911 GT2 RS at 7:24.[68] A few days later, the time was confirmed by Lexus as 7:14.64, a video was provided. OEM Bridgestone Potenza RE070 street tires had been used.

Engine

The Lexus LFA is powered by a 72-degree bank angle 4.8-liter V10 engine equipped with dual VVT-i carrying the 1LR-GUE designation with a maximum output of 412 kW (560 PS) delivered at 8,700 rpm. Its maximum torque output of 480 N·m (354 lb·ft) arrives at 6,800 rpm, 90 percent of which is available from 3,700 rpm. The engine redlines at 9,000 rpm, but with a fuel cutoff set at 9,500 rpm, and is constructed using forged aluminum pistons, forged titanium connecting rods, and solid titanium valves. The V angle of the LFA's V-10 engine is set to 72-degrees (as opposed to the 90-degree V angle present in a Dodge Viper's V-10) to fully balance the firing force from the pistons. This 72-degree angle allows for even firing from the pistons without the use of a split-journal crankshaft, thus improving engine efficiency as well as lowering overall weight. Dry sump lubrication prevents engine oil starvation through high speed corners and lowers the engine's center of mass. Air is fed directly from beneath the hood through a visible slit passing into a dual stage variable intake manifold and then into ten individual throttle bodies before finally exiting from a dual stage titanium muffler.

The LFA's engineers selected a V10 engine over an equivalent displacement V8 engine for its ability to rev higher, and over a V12 for its lower reciprocating mass, allowing for more rapid engine response. Lexus claims their engine can rev from idle to its redline in 0.6 seconds and an analog tachometer needle could not accurately track the LFA's changes in engine speeds. This necessitated the use of a digital tachometer which can instantly display engine speed. The engine reportedly weighs less than the manufacturer's own 3.5-liter 2GR-FE V6 engine. Engineers attempted to make the engine sound like that of a Formula One car with high revs, while at the same time maintaining reliability and vibration control. Along with other manufacturers such as Ferrari, Toyota had produced their own F1 engines and chassis designs. The exhaust note has been described by Toyota engineers as the "roar of an angel", and a US television spot later used the engine sound to shatter a champagne glass via resonance frequency.
The powerplant gives the LFA a weight-to-power ratio of 5.9 lb/hp and enables it to reach a top speed of around 325 km/h (202 mph).Not like the IS F Yamaha co-developed not only the engine cylinder heads but also the entire engine. The engine exceeds Euro V emissions. The engine is installed with a front mid-engine placement. According to Chief Engineer Haruhiko Tanahashi a front engine layout was selected instead of a mid engine layout as it is inherently more forgiving dynamically, affording less experienced drivers a wider safety net.

Transmission

The gearbox is a six-speed Automated Sequential Gearbox (electrohydraulic transmission) operated with paddle-shifter.

Chassis

The Lexus LFA's frame is made from an in-house designed and manufactured carbon fiber-reinforced polymer (CFRP) center monocoque with aluminum front and rear subframes. The subframes, which can be removed and replaced minimizing potential repair costs, are joined to the monocoque using a newly developed aluminum flanged collar designed to create a stronger joint. According to the manufacturer, the quality of the CRFP material matches that of aeronautical grades and is woven by a laser monitored circular loom, one of only two in the world.Overall 65% of the vehicle's total body mass is CFRP material while the remaining 35% is aluminum. Manufacturer data indicates that the use of CFRP saves 100 kg (220 lbs) over equivalent aluminum materials.

An electric power steering rack with a 14.3:1 gear ratio is used. The front suspension utilizes a double-wishbone arrangement and there is a multi-link arrangement at the rear with coil-over dampers at all wheels. The dampers are a monotube design, each with a remote fluid reservoir that includes an expanding and contracting bellows: a purely mechanical system. The LFA further features six-piston front and four-piston rear Brembo monobloc brake calipers with 390 mm (15.4 in) front and 360 mm (14.2 in) rear carbon ceramic discs controlled by Toyota's Electronically Controlled Brake brake-by-wire system. Forged 20-inch BBS wheels fitted with 265 mm (10.4 in) front and 305 mm (12.0 in) rear Bridgestone next-generation Potenza tires are standard. The LFA is equipped with a 3-mode Vehicle Dynamics Integrated Management (VDIM) stability control system with Sport setting.

To maintain a near ideal weight distribution, a rear transaxle is used, in addition to the mounting of the fuel tank ahead of the rear axle and the radiators at the rear. The windshield washer fluid reservoir is mounted in the center next to the fuel tank to improve further the center of weight. Overall 48% of the LFA's mass is distributed along the front wheels with 52% at the rear. The 73 L (16 imp gal; 19 US gal) fuel tank straddles the exhaust system keeping weight centered along the left-right axis. The engine is connected to the transaxle via a rigid carbon-fiber torque tube which the exhaust system runs directly below. This stacked driveshaft and exhaust arrangement decreases the width of the center tunnel allowing for centrally located seating.

Exterior

The production Lexus LFA has an overall length of 4,510 millimetres (177.4 in), while its wheelbase measures 2,610 millimetres (102.6 in), with a height of 48 inches (1,200 mm) and width of 74.6 in (1,895 mm). Compared to the prior 2007–2008 concepts, the production model is nearly 51 millimetres (2 in) longer, with identical width, height, and nearly same wheelbase dimensions.The exterior design of the LF-A concepts and the final production model was the work of car stylists led by Lexus Design general manager Kengo Matsumoto. The overall design ethos was based on the principle of form follows function, with aesthetics secondary to aerodynamics and operation.

The LFA body features sharp edges and cutoffs for improved aerodynamic performance, made possible by the carbon fiber body. The body was designed with an emphasis on downforce. There are air scoops located over the rear fenders which feed the aft-mounted radiators and help cool the brakes. A horizontal hood gap also feeds air to the engine. Two small aft vents expel air that is collected by an underbody air scoop and used to cool the titanium exhaust pipes. Dual hood ducts serve to move hot air away from the exhaust manifold.

The LFA's speed-sensitive rear wing incorporates a Gurney flap and deploys at speeds over 50 mph. With the wing retracted the LFA's body has a drag coefficient of Cd 0.31. The LFA body is offered with a choice of 28 standard exterior colors, along with 3 wheel colors and a matte black option. Additional "special colors" are available to order. The front and rear fenders, doors, roof rails, and rocker panels are made out of blast fiber reinforced sheet panels, while the tail lamps are light-emitting diode (LED) lights.

In operation the TFT display shows small digits in automatic mode; larger and bolder numbers in normal mode; inverted colors, moved redline, and stark numbers in sport mode, along with a programmable redline warning color change. The tachometer display also features an electric movable metal ring with layer acrylic plastic to create a 3D effect. The LFA further features a new driver and passenger seat-belt airbag design increases similar to the S-Class ESF safety concept car.

The steering wheel features a right-mounted start button and alloy paddle-shifters. To activate the vehicle the driver must insert the key beside the steering wheel then press the start button. Two octaves of engine sound are channeled into the cabin via twin ducts which connect the firewall with the intake manifold, with the sound tuned in the manner of an Ovation guitar. A 12-speaker Mark Levinson sound system with compact lightweight components was also developed for the interior. Custom-made Tumi suitcases are designed for the LFA interior, with a two-piece set made from carbon-fiber style materials and inscribed with the VIN; a smaller "concourse" case is for track days and short trips, while a larger "coastal" case is for longer trips.